Message about whale shark. Report: Whale Shark
To the question "What is the largest fish in the world?" most people will answer: blue whale or White shark. These statements are incorrect, since firstly, a whale is not a fish at all, but a mammal (which is often forgotten), and the second option is only half correct, since in the shark family there are much more major representative- . It is actually the largest in the world.
Often the dimensions exceed 10-14 meters, very rarely there are individuals up to 20 meters.
Whale sharks live in the warm tropical waters of the World Ocean. Most They spend their lives in small flocks. In places of abundance of food, flocks of hundreds of animals gather.
Despite huge size and a formidable appearance, it is completely harmless to humans. The whale shark feeds mainly on plankton, filtering it through the gills, and sometimes swallows small fish and jellyfish. During feeding, a whale shark passes through its gills in an hour 6 000 cubic meters of water.
The character of the shark is calm and slow. Swims at a speed of no more than 5 km/h. Whale sharks are completely at ease with divers who can pet them and even ride them on their backs, holding their fins.
The number of sharks of this species has always been small. But in Lately Due to uncontrolled poaching, their numbers are rapidly declining. Population of the South and South-East Asia They eat whale shark meat, even despite the complete ban on shark fishing. According to rough estimates, there are about 1,000 individuals left worldwide.
Despite the calm burrows of whale sharks, this species has been studied extremely poorly. This is due to the huge size of sharks and difficulties in transportation, as well as their small numbers.
The whale shark is difficult to confuse with other species. It is distinguished not only by its size, but also by the structure of its body. Not agile and thick body, relatively small head and flattened muzzle. The skin of an adult fish reaches 10 cm in thickness. The mouth of whale sharks is wide and is located at the end of the snout, and not under it, like other species. The 13 meter shark has a mouth of approximately 1.5 meters in diameter. The eyes are small and located almost on the edge of the muzzle; it is interesting that these fish cannot blink in principle, but they can still close their eyes, drawing them into the orbit and covering them with a thick leathery fold.
The whale shark was first described by Andrew Smith in 1828, based on a specimen harpooned off the coast. South Africa. Historically, there have been many different names (alternative scientific names) for family, genus and species.
A genus of sharks has now been named Rhincodon typus.
Geographical distribution
The whale shark has a very wide distribution range - in all tropical and temperate warm seas, with the exception of Mediterranean Sea. Distributed throughout the Atlantic Ocean, from Caribbean to the coast of central Brazil and from Senegal to the Gulf of Guinea. It is also found in Indian Ocean, including in the Red Sea and Persian Gulf. IN Pacific Ocean it lives from Japan to Australia, from Hawaii to Chile.
Habitat
Unlike most, the shark prefers an open habitat away from the coast. Research shows that this shark prefers warm waters with a surface temperature of about 21-30 ºC, with a high density of plankton.
The whale shark is thought to be migratory, but there is currently no direct evidence to support this hypothesis. Its movements may be associated with the presence of a nutrient medium.
Whale sharks can undertake either fairly localized or large-scale transoceanic migrations.
Every March and April, whale sharks are known to concentrate on the continental shelf of Australia's central and western coasts, particularly in the Ningaloo Reef area.
Whale sharks have been observed near La Paz, Mexico. Researchers showed that when these sharks fed at the surface, they swam with little or no head movement, gulping, opening and closing rhythmically gill slits.
Biology of the whale shark
Distinctive features
A streamlined body and a flattened head characterize the whale shark. The mouth is transverse, very large and almost at the tip of the muzzle. The gill slits are very large. First dorsal significantly larger than the second dorsal fin.
The whale shark has a "checkerboard" color pattern of light spots and stripes on a dark background.
Whale sharks are greyish, bluish or brownish in color, with spots. The belly is white.
One theory for shark coloration is that pigment spots may be an adaptation for radiation protection species that may spend a significant portion of their time in surface waters and be exposed to high levels ultraviolet radiation.
Teeth do not appear to play any role in nutrition.
Longitudinal protrusions appear on the body along the length of the body; perhaps they are intended to play some role in controlled movement.
The whale shark is the largest living fish. Maximum size 20 m. The smallest adult specimen was found 55 cm in length. Puberty in both sexes it occurs after 9 months. It is believed that the whale shark lives on average 60 years.
Whale sharks feed on plankton and nekton, including small crustaceans, schooling fish, and sometimes tuna and squid.
The whale shark feeds actively with its mouth open. By closing its mouth, it releases water through its gills.
During the short delay between the closing of the mouth and the opening of the gill flaps, plankton may become trapped in the dermal denticles lining the gill plates and pharynx.
The fine sieve, a unique modification of the gill rakers, forms a barrier to the passage of all but liquid, retaining for nutrition all organisms over 2 to 3 mm in diameter. Almost nothing except water passes through this sieve.
Coughing has been observed in whale sharks, a mechanism believed to be used to clear or flush out the accumulation of food particles from the gill rakers.
Whale sharks move their heads from side to side, vacuuming in seawater rich in plankton.
The whale shark's small eyes are located on the sides of its head. Because of this, vision may play a much smaller role than smell.
The whale shark is ovoviviparous.
In the past, the whale shark had little interest in humans. Currently, commercial fishing for whale sharks is limited, but the ban may be reduced as demand for food increases.
Of all those existing in the world. The size of the whale shark is second only to that estimated maximum size extinct megalodon.
About the life of a whale shark
For a long time it was unknown to scientists; only sailors traveling in tropical waters knew about it. The meeting with such a giant, of course, surprised and frightened them, and these emotions contributed to the emergence of many beliefs about monsters living in the oceans.
First scientific description
Zoologists first learned what a whale shark looks like in 1828. At that time, Andrew Smith, an English naturalist, was working in South Africa. He was given a small (4.50 m long) whale shark caught in Table Bay, on the shore of which the city of Cape Town is located. This is a small bay in southwest Africa in the Atlantic Ocean.
Smith did detailed description this new fish for science and gave it the Latin name - Rhincodon typus. This specimen was stuffed and subsequently sent to Paris. There is information that it is still kept in one of the museums in Paris. But this information has not been verified, and it is difficult to say in which museum this unique exhibit can be seen.
Characteristic features of appearance
The whale shark has unique appearance, by which she is recognized at first sight.
- A huge powerful body with a relatively small head.
- The head is flat, as if flattened; at the end of the snout this flattening is more pronounced.
- The mouth is terminal (located at the end of the snout); most other sharks have a mouth under the snout.
- The width of the mouth is up to one and a half meters. When fully opened, the mouth takes the shape of a very wide oval.
- In the corners of the mouth, leathery outgrowths similar to small antennae are clearly visible.
- The gill slits are wide and number five. They are long (up to 1.5 meters for a 12-meter specimen).
- Immediately behind the head, the body thickens greatly, forming a gentle hump, and then becomes thinner.
- There are two dorsal fins located closer to the caudal fin, the first of which is larger and looks like an equilateral triangle.
- The tail fin is characteristic of all sharks - it has different blades, the length of the upper blade is one and a half times longer than the lower one.
- Behind the head, along the sides and back, folds of skin are clearly visible, which, like long ridges, stretch to the tail.
- Large pectoral fins (up to 2.4 m long).
This is what a whale shark looks like through the eyes of the famous traveler Thor Heyerdahl: the description is quoted from his book (Thur Heyerdahl. The Kon-Tiki Expedition. “Ra”. Translated from Norwegian by L. Zhdanov. - M.: Mysl, 1972.)
“The head belonged to a gigantic monster, and it was so huge, so terrible that he sea serpent, had he appeared before us, he would not have struck us more strongly. Small eyes sat at the edges of the wide and flat muzzle, the toad's mouth with long fringes at the corners was at least one and a half meters wide. The powerful body ended in a long thin tail; the sharp vertical fin indicated that this was, in any case, not a whale. The body seemed brown in the water, but both it and the head were dotted with small white spots.
Skin and color
If you look at a photo of a whale shark, its color is striking:
- The main color of the dorsal part of the body is dark gray with brown or blue shades.
- Against this background, along the back and sides, there is a peculiar regular pattern of narrow transverse stripes of dirty white color, interspersed with rows of the same dirty white round spots.
- The head and pectoral fins are decorated with smaller and randomly located spots.
The skin of the body and fins is also “decorated” with a pattern of large number scratches This pattern is individual for each individual and does not change throughout life.
It is important that the spotted pattern is also constant for an individual. These patterns easily identify a specific whale shark, giving scientists the opportunity to conduct scientific observations of this species.
To identify differences in the spotted patterns on the skin of whale sharks, they used equipment used by astronomers to study the location of celestial bodies. The instruments were also effective in showing differences in the spotted patterns on the sharks' skin, as well as differences in the positions of stars in the sky.
The thickness of the skin on the back of a whale shark is up to 14 centimeters in large individuals. It is covered with the usual “skin teeth” - placoid scales, consisting of a basal plate and a sharp spine extending upward from it. However, the whale shark has scales that are different from those of other sharks: the plate is very small, and the sharp spines are well developed and strongly curved back. Perhaps this serves to improve the hydrodynamic properties of the shark's body.
The ventral side of the body, also covered with placoid scales, is characterized by thinner skin than on the back (about 30% thinner). Very often the shark turns its back to the approaching diver, probably due to the weaker protection of its belly.
Dimensions of the largest shark
The maximum size of the whale shark was clarified until the end of the 1990s, when the first reliable scientific information appeared about the largest specimen of this type of fish: its length turned out to be 20 meters. How much does a whale shark of this size weigh? Its weight was 34 tons.
Ichthyologists use every opportunity to take measurements different parts the body of this sea giant. This happened in southern state Tamil Nadu in 2002 in India, when a young individual ended up in the hands of Indian scientists. Scientists measured all her body parameters with high accuracy:
- The length of the whale shark was 478 centimeters.
- The mouth was 77 centimeters wide.
- The length of the upper large blade of the caudal fin was 115 centimeters.
- Eye parameters: length – 4 centimeters, width – 3.5 centimeters.
Data were obtained on how much a whale shark almost 5 meters long weighs: weight 1700 kg. Most often, people encounter whale sharks no larger than 12 meters.
Favorite places of whale sharks in the ocean
Where does the whale shark live? Not in cold water. She loves warmth, and therefore can be found in low latitudes all oceans. The highest latitude where it descends to the south and rises to the north is 40 degrees, but very rarely. Its usual range is south of 30 degrees north and north of 35 degrees south latitude.
The water temperature of the surface layer in the areas where the whale shark lives is in the range of 21-25 degrees, with a constant influx of deeper, cooler layers of water. The salinity in these places is very high - up to 35 ppm.
Scientists suggest that such preferences for water parameters in sharks are associated with big amount planktonic organisms in these places, which form the basis of its diet. There is information that whale sharks have been spotted even in river mouths, where salinity is lower than oceanic, but there are dense accumulations of plankton.
Whale sharks have favorite places in the world’s oceans, where they are found more often and in large numbers:
- Taiwan Island and Seychelles– here they are present throughout the year, although the maximum occurs in summer months and the end of autumn (according to the generally accepted calendar).
- Areas adjacent to the eastern and south- east coast Africa is the second place favored by whale sharks, but also with seasonal peaks in numbers. Scientists estimate that 1/5 of the world's shark population lives off the coast of Mozambique.
- The Philippines, some places off the coast of Australia, Chile and the Gulf of Mexico are places where whale sharks are common.
Whale sharks rarely visit other places in the world's oceans within their range and only seasonally.
Whale sharks' favorite food and feeding method
Is the whale shark a predator or not? If you look into her mouth, the answer is obvious. She has no teeth great amount– several thousand (maximum up to 15,000). Even the most gigantic whale shark has small, completely “non-shark” teeth, no more than 6 millimeters high.
Of course, this size of teeth is a very peculiar adaptation to obtaining food, because their owner does not bite prey, like all her other relatives (with the exception of giant shark). Such a huge number of teeth helps to “lock” the prey in the mouth, in other words, to close the mouth very tightly.
Like baleen whales, this gigantic shark slowly “grazes” in the ocean, filtering planktonic organisms from the water. The filtering apparatus is cartilaginous plates (20 of them), located between adjacent gill arches. This whole structure looks like a lattice with a mesh width of no more than 3 millimeters. These plates also contain skin teeth.
With its mouth wide open, the shark takes in water, then closes it. The water is filtered through the gill slits. And all the planktonic inhabitants that fall into the shark’s mouth remain in the mouth and are directed through the esophagus, which is unusually narrow for such a giant (only 10 centimeters in diameter) into the stomach. It is clear that in order to get enough of such small food, you need to constantly get it. This is what whale sharks do constantly – 7-8 hours every day. In one hour, up to six thousand cubic meters of water are passed through the shark’s mouth.
Watch the video and notice how wide the whale shark's gill slits open as it filters the water and food.
In the photo of a whale shark, you can see how a school small fish pulled forcefully into her wide-open mouth.
Therefore, the answer to the question “is a whale shark a predator or not” is the word “no”.
The menu consists of everything that ends up in her mouth and is able to “squeeze” into her “miniature” esophagus. Here is the list:
- zooplankton (jellyfish, small squids, crustaceans and others), the size of which is measured in several millimeters;
- medium-sized species of schooling fish (sardine, anchovy, small mackerel and sometimes tuna).
When a whale shark feeds, its movement speed is minimal, and it often stops and hovers in the water. It happens that she holds the body in an almost vertical position to the surface. It often sucks in food objects floating in the very surface layer of water: usually these are small copepod crustaceans and fish larvae. In this case, a small part of its mouth is visible above the water.
This giant, slowly plowing through the expanses of tropical waters, for a long time was the cause of many rumors and legends: frightened sailors described him in their stories as a terrible monster living in the ocean abyss. However, it later turned out that the lonely wanderer of the depths was not a terrible sea monster at all, but a huge whale shark, which to this day is the most mysterious fish on the planet.
![](https://i0.wp.com/rybki.guru/wp-content/uploads/2018/07/citovaja-min.jpg)
Main characteristics
This big shark hid from the eyes of researchers for a very long time, thereby serving as a reason for the spread of various beliefs. And indeed, the private descriptions were so gloomy that they could be recognized as anyone but an ordinary fish.
First official sighting of a whale shark took place in 1828. It was a 4.5 meter long specimen taken off the coast of South Africa by the popular English naturalist Andrew Smith. It was he who first described the species, giving it the name Rhincodon types.
The whale shark is the largest representative of the shark family, surpassing in size not only its closest relatives, but also all other species of fish that exist today. It received the name “whale” not only due to its impressive body size, but also to its peculiar way of feeding, as well as the structure of its jaw (all these features make the fish more like a whale than its shark relatives).
Appearance and structure
This inhabitant water world difficult to confuse with its other representatives, since the whale shark looks very unique and, in addition to its large size, has a number of other characteristic features. Basic external features type:
![](https://i2.wp.com/rybki.guru/wp-content/uploads/2018/07/rhincodon_typus-.jpg)
Giant size
For many decades it was officially believed that maximum length the whale shark is approximately 12.65 m. However, some unverified sources insisted that the fish could be larger in size. Nevertheless, scientists did not consider such information reliable and took the parameters of registered individuals as a basis. But already at the end of the twentieth century, new official data appeared about a specimen 20 meters long and weighing 34 tons. Since then, this figure is no longer a myth, but such giants are still extremely rare today.
![](https://i1.wp.com/rybki.guru/wp-content/uploads/2018/07/razmery_giganta.jpg)
Features of color
You can recognize a shark by its very characteristic coloring. The sides and back of this fish usually have a dark gray background, which is quite in the right order there are transverse and longitudinal narrow stripes of pale yellow or dirty white color. Between the stripes there are almost uniform round spots of the same shade. The pectoral fins and head have the same markings, but in these places they are smaller and more densely and chaotically scattered. Bottom part the body is painted in a light gray tone.
The skin of the body and fins has many peculiar scratches that form a characteristic pattern. Each individual is endowed with its own unique pattern, which does not change with age, by which observers recognize it.
Habitat and food
The favorite places of these giants are moderately warm and tropical waters oceans and seas, so the species is most often found in areas where the temperature of the surface layer of water is between 21 and 26 °C. Scientists suggest that such thermophilicity is associated not so much with physiological needs as with the food preferences of the giant, since in places with its largest population, as a rule, and mass gatherings planktonic organisms are the main food of this fish.
Areas where whale sharks live:
- Seychelles and Taiwan - they are present near these islands all year round, although the greatest concentration is observed in the summer and autumn periods.
- Regions adjacent to the southeast and east coasts African continent. Scientists estimate that Mozambique's coastal regions are home to a fifth of total number kind.
- Small populations are also found in the waters of Australia, the Philippines, Chile and the Gulf of Mexico.
![](https://i0.wp.com/rybki.guru/wp-content/uploads/2018/07/kitovaya-akula.jpg)
Despite their belonging to the family of predators and a huge number of teeth, these fish are not at all bloodthirsty, and their diet mainly includes:
- zooplankton;
- small species of schooling fish, namely anchovy, tuna, sardine and small mackerel.
They need teeth not for tearing prey, but so that the latter does not escape from their huge mouth. In fact, these strong organs are given to the giant as a kind of “locks” for locking food.
Like baleen whales, the shark slowly “grazes” in the ocean, sifting out plankton. To do this, she opens her mouth very wide, taking in a large number of water, after which the huge mouth closes, and the liquid exits through gills equipped with special filters. As a result, only those remain in the mouth aquatic life, which are able to “squeeze” into the extremely narrow esophagus (diameter only about 10 cm) of the giant. Thus, in order to be completely satiated, the whale shark feeds throughout the whole day (about 8-9 hours a day), while passing up to 6 thousand cubic meters of water per hour through its mouth and gill slits.
![](https://i1.wp.com/rybki.guru/wp-content/uploads/2018/07/kitovaja.jpg)
A little about reproduction
Watching this huge fish has been going on for more than a century, but scientists still have very little information about its reproduction. First of all, it is known that she is ovoviviparous, i.e., embryos develop in the womb in characteristic egg capsules, after which they hatch there and are then born into the world.
Newborn sharks are about 0.5 meters long and can go without food for quite a long time, since they gain sufficient quantity internal nutritional reserves. Proof of this is the case when a living and fully developed baby shark was removed from the belly of a caught shark. The baby was placed in an aquarium, where for the first two weeks he ate absolutely nothing, but was cheerful and active.
Research at the end of the twentieth century also found that this representative of the shark goes through an extremely long process of puberty, lasting up to 30-50 years. The full lifespan of the species ranges from 70 to 100 years. There is unverified information even about 150-year-old individuals, but this has not been proven by science.
Behavior and danger to humans
Most ichthyologists describe this fish as a leisurely and extremely calm creature. The species prefers warm, near-surface layers of water, but if necessary, it can dive to a depth of up to 700 meters. The shark swims very slowly - about 5 km/h, and in most cases less. Active throughout the day, and sleeps in short intervals, regardless of day or night.
Basically, these giants prefer to stay completely in small groups or even live alone. It is extremely rare to form mass aggregations of several hundred individuals.
Despite its enormous size, the whale shark is generally considered absolutely safe for humans. This sluggish, inert and slow fish has never attacked people, which is what numerous divers take advantage of with pleasure, not only swimming close to the giant, but also climbing onto its back. However, ichthyologists are not so careless and consider the whale shark as a potential dangerous look, since a wounded individual can go into a rage and not only damage the ship, but also kill a person with one small blow of its tail.
![](https://i0.wp.com/rybki.guru/wp-content/uploads/2018/07/whale-shark-and-man.jpg)
Threats and natural enemies
Whale sharks have never been a numerous species, but today there is evidence that there are only about a thousand individuals left on the planet. This sad situation has been led to by mass commercial fishing, which is most developed in some regions of Asia, as well as in Taiwan and the Philippines, where the meat of this fish is highly valued.
In addition to the main enemy - man, the whale shark has enemies among its relatives. It is mainly attacked by predators such as blue shark and marlin. Often a killer whale joins them. In most cases, the victims are young individuals, but there are also attacks on adult whale sharks. This happens due to the absolute defenselessness of the fish, since its impressive size and thick skin cannot always save it from the enemy, and this giant has no other means of defense.
Significance in culture and tourism
Even in those regions where the shark is most common, it does not have a special role in the culture of a particular nationality. And only Japanese and Vietnamese fishermen treat this giant with special trepidation. So, in Japan it is believed that meeting a giant fish is a good omen. Also in this country, where seafood forms the basis of the daily diet, whale shark meat is practically not consumed.
Vietnamese sailors also treat it with great respect, believing that fish not only brings good luck, but is also a kind of sea deity. The Vietnamese even recorded their attitude in a peculiar popular name this giant, which is literally translated from their language as “Mr. Fish”.
The shark has acquired great importance in the tourism business. In some countries, where the species is still relatively common, entire tours are organized in which everyone can not only watch the giant from aboard a sea vessel, but even get close to it by scuba diving.
Diving tours are especially popular in Mexico, the USA, the Maldives and Seychelles, Australia, and the Caribbean. Unfortunately, such human entertainment does not contribute in any way to increasing the population, but, on the contrary, negatively affects the peace and lifestyle of these largest fish, of which there are already only a few left.
The one who still thinks that the most big fish on the planet - blue, he is deeply mistaken. Whales are classified as mammals, and among them he is truly the very best. And here whale shark is the most largest living fish.
Description and features of the whale shark
This gigantic species was hidden from the eyes of ichthyologists for a long time and was discovered and described relatively recently - in 1928. Of course, even in ancient times there were rumors about a monster of unprecedented size living in deep sea, many fishermen saw its outlines through the water.
But for the first time, a scientist from England, Andrew Smith, was lucky enough to see it with his own eyes; it was he who explained in detail to zoologists about its appearance and building. A 4.5 meter long fish caught off the coast of Cape Town was named Rhincodon typus ( whale shark).
Most likely, the naturalist came across a teenager, because average length this underwater inhabitant fluctuates between 10-12 meters, whale shark weight– 12-14 tons. The most big whale shark, discovered at the end of the last century, weighed 34 tons and reached a length of 20 meters.
It received its name not for its impressive size, but for the structure of its jaw: its mouth is located strictly in the middle of the head, like in real whales, and not at all in the lower part, like in most of its shark relatives.
The whale shark is so different from its fellows that it is classified into a separate family, consisting of one genus and one species - Rhincodon typus. The massive body of the whale shark is covered with special protective scales, each such plate is hidden under the skin, and on the surface you can only notice razor-sharp tips, reminiscent of teeth in shape.
The scales are covered with an enamel-like substance called vitrodentin and are as strong as shark teeth. Such armor is called placoid and is present in all species. The skin of a whale shark can reach 14 cm in thickness. Subcutaneous fat layer– all 20 cm.
The length of a whale shark can exceed 10 meters
From the back, the whale shark is painted dark gray with bluish and brown streaks. Light whitish spots are scattered across the dark main background round shape. On the head, fins and tail they are smaller and chaotic, while on the back they are arranged in a beautiful geometric pattern of regular transverse stripes. Each shark has a unique pattern, similar to a human fingerprint. The gigantic shark belly is off-white or slightly yellowish in color.
The head has a flattened shape, especially towards the end of the snout. During feeding, the mouth opens wide, forming something like an oval. Whale shark teeth Many will be disappointed: the jaws are equipped with small teeth (up to 6 mm), but the number will surprise you - there are about 15 thousand of them!
On the sides of the mouth there are deep-set small eyes; in particularly large individuals the eyeballs do not exceed the size of a golf ball. Sharks do not know how to blink, however, if any large object approaches the eye, the fish pulls the eye inward and covers it with a special skin fold.
Interesting fact: whale shark, like other representatives of the shark tribe, with a lack of oxygen in the water, is able to turn off part of its brain and hibernate to conserve energy and vitality. It is also curious that sharks do not feel pain: their body produces special substance, which blocks unpleasant sensations.
Whale shark lifestyle and habitat
Whale shark, dimensions which determine the absence natural enemies, slowly plows the expanses of the world's oceans at a speed of no more than 5 km/h. This majestic creature, like a submarine, slowly glides through the water, periodically opening its mouth to swallow food.
The pattern of spots on a whale shark is as unique as a human fingerprint.
Whale sharks are slow and apathetic creatures that show neither aggression nor interest. You can often find whale shark photo almost in an embrace with the diver: indeed, this species does not pose a danger to humans and allows you to swim close to itself, touch the body, or even ride while holding the dorsal fin.
The only thing that can happen is a blow from a powerful shark tail, which can, if not kill, then greatly injure. According to scientific research, whale sharks live in small groups, less often alone, but sometimes, in places of seasonal accumulation of school fish, their number can reach up to hundreds.
So, off the coast of Yucatan in 2009, ichthyologists counted more than 400 individuals; this accumulation was caused by the abundance of freshly spawned eggs, which sharks feasted on.
Including cetaceans, they must constantly be on the move, since they do not have swim bladder. The muscles of the fins help the fish's heart pump blood and maintain sufficient blood flow for life. They never sleep and can only sink to the bottom or hide in underwater caves to rest.
What helps sharks stay afloat is their huge liver, which is 60% fatty tissue. But this is not enough for the whale shark; it has to float to the surface and swallow air so as not to go to the bottom. The whale shark is a pelagic species, that is, living in the upper layers of the world's oceans. Usually it does not descend below a depth of 70 m, although it is capable of diving to 700 m.
Because of this feature, whale sharks often encounter large by sea vessels, are injured or even die. Sharks cannot stop or suddenly slow down, since in this case the flow of oxygen through the gills is minimal and the fish can suffocate.
Whale sharks are thermophilic. Surface water in the places where they live, they are heated to 21-25°C. These titans will not be found north or south of the 40th parallel. This type found in the waters of the Pacific, Indian and Atlantic Oceans.
Whale sharks also have their own favorite places: eastern and southeast coast, area of the Seychelles archipelago, Taiwan island, Gulf of Mexico, Philippines, Australian coast. Scientists estimate that 20% of the world's population lives off the coast of Mozambique.
Whale shark feeding
It's paradoxical, but whale shark is not considered a predator in the usual sense. Despite its colossal dimensions, the whale shark does not attack other large animals or fish, but feeds on zooplankton, and small fish, falling into her immense mouth. Sardines, anchovies, mackerel, krill, some types of mackerel, small tuna, squid and the so-called " living dust“—that’s the entire diet of this giant.
It's amazing to watch this giant feed. The shark opens its huge mouth wide open, the diameter of which can reach 1.5 meters, and captures sea water along with small animals. Then the mouth closes, the water is filtered and exits through the gill slits, and the strained food goes straight into the stomach.
It has a whole filtering apparatus, consisting of 20 cartilaginous plates that connect the gill arches, forming a kind of lattice. Small teeth help keep food in the mouth. This way of eating is not only whale shark: giant and largemouth also eat in a similar way.
The whale shark has a very narrow esophagus (about 10 cm in diameter). To push through so much small hole sufficient amount of food, this huge fish has to spend about 7-8 hours a day getting food.
Shark gills pump about 6,000 m³ of fluid per hour. The whale shark cannot be called a glutton: it eats only 100-200 kg per day, which is only 0.6-1.3% of its own weight.
Reproduction and lifespan of the whale shark
For a long time there was almost no reliable data on how the whale shark reproduces. It has only recently begun to be successfully kept in captivity, in huge aquariums, where such giants have enough freedom.
Today there are only 140 of them in the world. Thanks modern technologies, allowing the creation of such grandiose structures, it became possible to observe the life of these creatures and study their behavior.
Whale sharks are ovoviviparous cartilaginous fish. In my womb whale shark length 10-12 meters can simultaneously bear up to 300 embryos, which are enclosed in special capsules like eggs. The baby sharks hatch inside the female and are born into the world as completely independent and viable individuals. The length of a newborn whale shark is 40-60 cm.
Cubs at birth have a fairly large reserve nutrients, which allows them to go without feeding for a long time. There is a known case when a baby shark was pulled out of a harpooned shark and placed in large aquarium: the cub survived, but began to eat only after 17 days. The gestation period of a whale shark, according to scientists, is about 2 years. During this period, the female leaves the group and wanders alone.
Ichthyologists are inclined to believe that whale sharks reach sexual maturity at a body length of 4.5 m (according to another version, from 8). The age at this point can be 30-50 years.
The lifespan of these giant sea creatures- about 70 years, some live 100. But individuals who have lived 150 years or more are still an exaggeration. Today, whale sharks are monitored, tagged with radio beacons and their migration routes are tracked. There are only about a thousand such “marked” individuals; it is unknown how many more are wandering in the depths.
About the whale shark, white or any other, you can talk for hours: each of them is the whole world, small space and vast universe. It is foolish to think that we know everything about them - their simplicity is apparent, and the accessibility of study is illusory. Having lived on Earth for millions of years, they are still full of secrets and never cease to amaze researchers.
![](https://i2.wp.com/givotniymir.ru/wp-content/uploads/2017/09/%D0%B6%D0%B8%D0%B2%D0%BE%D1%82%D0%BD%D1%8B%D0%B9-%D0%BC%D0%B8%D1%80-%D1%81%D0%B0%D0%B9%D1%82.jpg)